"I'm having to move up my schedule," Roberts explained Thursday morning."I am very blessed," she added. "Forty percent of Americans can't even take a sick day, and here I know that I'm going to have a job when I come back."

Friday Aug. 31 had been Roberts' planned final day as she gears up for a bone marrow transplant. Back in June, Roberts revealed to fans to that she is battling myelodysplastic syndrome (MDS), a rare blood and bone marrow disorder -- with her sister, Sally, acting as the donor.

"My doctors tell me I'm going to beat this -- and I know it's true," Roberts, who beat breast cancer five years ago, wrote on GMA's website. "They say I'm younger and fitter than most people who confront this disease and will be cured."